Distance measurement system

Abstract

The present invention relates to a distance measurement system 100 for measuring the distance between a first transceiver 110 and second transceivers 120, 124. The distance measurement system 100 includes a first transceiver 110 having a first time zone 112, a second transceiver 120 having a second time zone 122, and a control unit 130 having a control unit time zone 132. The second transceiver 120 is configured to determine a time zone relationship Delta_SE2_SE1 between the second transceiver 120 and the first transceiver 110 and send the time zone relationship Delta_SE2_SE1 to the control unit 130. The control unit 130 is configured to receive the time zone relationship Delta_SE2_SE1 and use the time zone relationship Delta_SE2_SE1 to determine a time zone relationship Delta_ST_SE1 between the control unit time zone 132 and the first transceiver 110. The first transceiver is configured to send a distance measurement command to the second transceiver 120 at a defined moment or within a defined time period in the first time zone 112. The first transceiver 110 is further configured to send a measurement signal at another defined moment, and the second transceiver 120 is further configured to switch from an inactive receiving or measuring state to an active receiving or measuring state at a defined moment or within a defined time period, then receive the distance measurement command or the measurement signal, perform a distance measurement, and switch back to the inactive measurement state.

Description

Technical Field

[0001] The present invention relates to a distance measurement system for measuring the distance between a first transceiver and a second transceiver, a smart phone including the first transceiver, a vehicle including the second transceiver, a method for measuring the distance between the first transceiver and the second transceiver, the use of the distance measurement system for a building access system, and the use of the distance measurement system for non-contact payment or cash withdrawal. Background Art

[0002] A smart phone or a radio key can be used to unlock a vehicle, such as a car. In response to a low-frequency signal, for example, from an unlocking circuit of the vehicle (which is emitted once the user touches the door handle), these smart phones or radio keys measure the signal strength of the received signal and send the measured value back to the unlocking circuit. The unlocking circuit can estimate the approximate position based on the signal strength and then estimate the distance of the key. If the distance is recognized to be within a predefined range, the unlocking circuit unlocks the vehicle. An attacker can use a relay transponder to interfere with the signal strength measurement. The relay transponder amplifies the signal from the unlocking circuit and relays it to the radio key, and then the radio key responds and sends a response signal containing the measured value of the signal strength back to the unlocking circuit via the transponder. Therefore, the unlocking circuit receives the measured value of the signal strength from the key, and this measured value of the signal strength indicates that the key is close to the vehicle (even if the distance is large), and the vehicle door is opened.

[0003] Verifying whether the user or the radio key is actually close to the vehicle can be achieved by distance measurement, for example, by measuring the transmission time of a radio frequency signal between a communication device in the smart phone or the radio key and a communication device in or on the vehicle. The important factor here is to minimize the energy required for this purpose, for example, in the distance measurement device in the smart phone or the vehicle. Summary of the Invention

[0004] Therefore, an object of the present invention is to provide a system that can be used to minimize the energy required in the system components involved, thereby minimizing the costs therein.

[0005] This object is achieved by a distance measurement system for measuring the distance between a first transceiver and a second transceiver, a vehicle, a method for measuring the distance between the first transceiver and the second transceiver, and uses. Other embodiments, the following description, and the drawings relate to advantageous embodiments.

[0006] Technical terms are used in the sense known to those skilled in the art. When certain terms are given specific meanings, the definitions of the terms will be given below in the context of using these terms.

[0007] For example, the term "command" in the "distance command" should be understood in the present disclosure as representing a digital or analog signal transmitted by wire or wirelessly. The digital signal can here be, for example, an encoded instruction consisting of one or more bits, or a voltage originating from a digital circuit and which can have two values. Correspondingly, the analog signal is typically generated by, for example, an analog circuit. For example, in the present case, the analog signal can also be a voltage that constitutes the supply voltage of the signal strength detection device. Thus, in this context, a "command" is a signal that causes a measurement and is to be distinguished from the signal being measured.

[0008] According to a first aspect, there is provided a distance measurement system for measuring the distance between a first transceiver (such as a radio key or a smartphone) and a second transceiver (such as a distance measurement unit on or in a vehicle) to verify a signal strength measurement value or to locate the smartphone and to unlock or lock the vehicle. The distance measurement system includes a first transceiver having a first time zone, a second transceiver having a second time zone, and a control unit having a control unit time zone. The time zone can here be understood as the time set by a clock or a clock chip in the associated component. The second transceiver is configured to determine a time zone relationship Delta_SE2_SE1 between the second transceiver and the first transceiver or the time zone of the first transceiver, and to send the time zone relationship Delta_SE2_SE1 to the control unit. The control unit is configured to receive the time zone relationship Delta_SE2_SE1 and to use the time zone relationship Delta_SE2_SE1 to determine a time zone relationship Delta_ST_SE1 between the control unit time zone and the first transceiver. The first transceiver is configured to send a distance measurement command to the second transceiver at a defined moment or a defined time period in the first time zone. For example, the defined moment is a whole second or a whole minute or a time based on the time zone of the first transceiver, and the defined moment is either system-defined or transmitted to the second transceiver at least once. This moment is known to the second transceiver because the time of the first transceiver is known through the determined time zone relationship. The first transceiver is further configured to send a measurement signal at another defined moment, and the second transceiver is further configured to switch from an inactive reception or measurement state to an active reception or measurement state at the defined moment or the defined time period, then to receive the distance measurement command or the measurement signal, perform a distance measurement and again switch to the inactive measurement state.

[0009] In other words, first the difference in the clocks or time zones between the first transceiver and the second transceiver is determined, and then the difference in the clocks or time zones between the second transceiver and the control unit is determined, so that all time relationships are known.

[0010] The differences Delta_SE2_SE1 and Delta_ST_SE1 thus represent a clock offset or a time zone offset, thereby enabling a form of "synchronization", but the clock is not readjusted or affected by the "synchronization". As described above, once the control unit and the second transceiver know the time zone, distance measurement can be performed. For example, the distance measurement can be performed at multiple predefined moments (e.g., a few seconds after the "synchronization").

[0011] This enables the measurement to be performed at a specific moment within a very short time interval, and the components involved in the measurement can be selectively turned on for the measurement and then turned off again or put into a sleep state until the next measurement. This saves the energy of these components involved, thereby extending their service life or maintenance interval in cases where they are battery-powered, for example, and / or means that they require a smaller energy supply (e.g., a smaller power supply unit). A smaller power supply unit is particularly suitable for the second transceiver that measures the measurement signal, such as the measurement unit in a vehicle.

[0012] According to one embodiment, the first transceiver includes a first clock that defines a first time zone. The second transceiver includes a second clock that defines a second time zone. The first control unit includes a control unit clock that defines the time zone of the first control unit. The first clock, the second clock, and the control unit clock are configured to define their respective defined time zones independently of other time zones. This means that the clocks in all components can run completely independently of each other and do not need to run in the same way. It is sufficient to determine and know the time difference between the time zones, and then appropriately add or subtract the time difference. Since the clocks run independently of each other, the differences Delta_SE2_SE1 and Delta_ST_SE1 between the time zones are determined or updated regularly.

[0013] According to one embodiment, the first transceiver includes a time communication module and a measurement communication module. The second transceiver includes a time communication module corresponding to the first transceiver and a measurement communication module corresponding to the first transceiver. The time communication module of the first transceiver is configured to send a message for determining the time zone relationship between the first transceiver and the second transceiver to the second transceiver via a first communication protocol, and the measurement communication module of the first transceiver is configured to send a measurement signal for determining the distance between the first transceiver and the second transceiver to the second transceiver via a second communication protocol.

[0014] This means that the determination of the time difference between time zones can be performed by the time communication module independently of the measurement performed via the second module, i.e., the measurement communication module. For example, the determination of the time zone difference can be performed by the time communication module within a larger operating range of the communication connection, but at longer time intervals than the distance measurement as needed and with the energy required therefor. In terms of determining the clock offset and measuring the distance, both the time communication module and the measurement communication module are only activated at the time when the respective communication actually occurs. During the communication-free time period, the time communication module and the measurement communication module are turned off or deactivated, or switched to the standby state or the sleep state.

[0015] According to one embodiment, the first communication protocol is a Bluetooth communication protocol, and the second communication protocol is a UWB (Ultra-Wideband) communication protocol. For example, a Bluetooth profile that defines a transmit timestamp and a receive timestamp can be used. The comparison of time zones can be performed via Bluetooth communication within a relatively large range (e.g., ten meters or dozens of meters). The actual distance measurement is preferably performed via UWB within a shorter range (e.g., up to a few meters). Here, a special protocol can be used, in which, for example, the first transceiver and the second transceiver repeatedly send timestamps back and forth to obtain an accurate measurement value.

[0016] According to one embodiment, the message for determining the time zone relationship between the first transceiver and the second transceiver contains a transmit timestamp, and the second transceiver is configured to determine the time zone relationship based on the transmit timestamp and the receive timestamp. Preferably, the same principle also applies to all cases of determining the time zone relationship, i.e., also to between the second transceiver and the control unit.

[0017] According to one embodiment, the distance measurement is a transmission time measurement, and the first transceiver and the second transceiver are configured to determine the transmission time via the communication between the first transceiver and the second transceiver. Through the communication, the transmit timestamp and the receive timestamp can be transmitted, and the transmission time is determined based on the difference between the two. Therefore, there is no need to perform clock error correction via, for example, triangulation, which is common in satellite navigation.

[0018] According to one embodiment, the distance measurement system further includes one or more additional second transceivers, where each of these additional second transceivers has its own independent time zone and is configured to receive the time zone relationship Delta_SE2_SE1 from the second transceiver or the control unit and, in each case, determine therefrom its own time zone relationship Delta_SE2x_SE1 relative to the first transceiver. These additional second transceivers are also configured to receive a distance measurement signal from the control unit at or within a defined moment, switch from an inactive measurement state to an active measurement state at this moment, then receive the measurement signal from these transceivers, perform distance measurement, and switch back to the inactive measurement state. The above-mentioned second transceiver can thus be regarded as a "master transceiver" that determines the time zone difference relative to the first transceiver and sends this difference to another second transceiver, so that they do not have to communicate with the first transceiver to determine the time zone difference. The additional second transceivers preferably have the same design as the master transceiver. This allows the control unit to flexibly select each of these second transceivers as the master transceiver.

[0019] According to another embodiment, the control unit is integrated in the second transceiver.

[0020] According to another aspect, there is provided a smart phone including the first transceiver as described above. The smart phone may include various communication modules, such as mobile communication, Bluetooth, NFC (Near Field Communication), and can be relatively easily controlled by an application program, for example. Thus, there is no need to carry other devices. Therefore, the smart phone is suitable for use as the first transceiver.

[0021] According to another aspect, there is provided a vehicle including a second transceiver and a control unit. The vehicle may include a plurality of transceivers powered by the vehicle power supply. The transceivers and the control unit may be connected to each other by wire or wirelessly. For example, the antenna of the transceiver may be installed on the roof or at a corner to have as large and unobstructed a radiation area as possible. For example, such a vehicle may be a car, a bus, a truck, or a rail vehicle.

[0022] According to another aspect, there is provided a method for measuring the distance between a first transceiver and a second transceiver, the method including the following steps:

[0023] Determine, by the second transceiver, the time zone relationship Delta_SE2_SE1 between the second transceiver and the first transceiver and send the time zone relationship Delta_SE2_SE1 to the control unit.

[0024] The control unit (130) receives the time zone relationship Delta_SE2_SE1 and uses the time zone relationship Delta_SE2_SE1 to determine the time zone relationship Delta_ST_SE1 between the control unit time zone and the first transceiver (110).

[0025] Send a distance measurement command to the second transceiver at or within the defined moment in the first time zone.

[0026] The first transceiver sends a measurement signal at another defined moment.

[0027] At the defined moment or within the defined time period, switch the second transceiver from the inactive measurement state to the active measurement state, receive the measurement signal, perform distance measurement, and the second transceiver switches back to the inactive measurement state.

[0028] The steps of the method correspond to the description of the above system. Regarding the order, the determination of the time zone difference can also be carried out in such a way that, for example, the components in the vehicle, namely the second transceiver and another second transceiver and the control unit, are carried out first, and then the determination of the time zone difference between the first time zone and the second time zone is carried out.

[0029] For example, a distance measurement system can be used to verify whether the user carrying the first transceiver is actually close to the transceiver. For example, regarding a vehicle, the following usage scenarios are possible:

[0030] The user approaches the vehicle from a long distance to open the vehicle. After verifying the user's proximity, unlock the vehicle.

[0031] The user enters the opened vehicle or the open vehicle, such as a construction machine, and starts the vehicle. For example, starting can only be carried out after verifying the user's proximity.

[0032] The user leaves the vehicle after triggering the closing.

[0033] The user leaves the vehicle and walks a long distance, so that once the user's proximity can no longer be verified, the vehicle will be locked.

[0034] The user approaches the vehicle from a long distance but stays close to the vehicle for a long time without opening the door.

[0035] [[ID=3,3]]The user leaves the vehicle, locks the vehicle and stays within the area covered by the time communication module or the measurement communication module, for example when the user stays in the house near the vehicle. In this case, the verification prevents the vehicle from remaining open because the space verification range has been exited.

[0036] According to another aspect, the distance measurement system is used for a building access system. In this usage, the building is only unlocked after verifying the user's proximity.

[0037] According to another aspect, the distance measurement system is used for contactless payment or cash withdrawal, so payment or cash withdrawal is only possible after the proximity of the user has been verified.

[0038] Synergistic effects can be produced by different combinations of the embodiments, even if the synergistic effects may not be described in detail.

[0039] It must also be noted that while all method-related embodiments of the present invention can be implemented in the order of the steps described, this does not have to be the only and necessary order of the steps of the method. Unless otherwise explicitly stated below, the methods presented herein can be implemented using different orders of the disclosed steps without departing from the associated method embodiments.

[0040] When implementing the claimed invention, those skilled in the art can understand and implement other variations of the disclosed embodiments by studying the drawings, the disclosure, and the appended claims. The use of the word "including" in the claims does not exclude other elements or steps, and the indefinite article "a" does not exclude more than one. A single processor or another unit can implement the functions of multiple objectives or steps set forth in the claims. The fact that certain measures are defined in mutually dependent claims does not mean that combinations of these measures cannot be used advantageously. The reference signs in the claims should not be construed as limiting the scope of the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The exemplary embodiments of the present invention are explained in more detail below with reference to the schematic drawings, in which:

[0042] Figure 1 A block diagram of a distance measurement system according to an exemplary embodiment is shown;

[0043] Figure 2 A block diagram of a smart phone having a first transceiver is shown;

[0044] Figure 3 A block diagram of a vehicle having a control unit and a second transceiver is shown;

[0045] Figure 4 A flowchart of a method for measuring the distance between a first transceiver and a second transceiver is shown. DETAILED DESCRIPTION

[0046] Figure 1A block diagram of a distance measurement system 100 for measuring the distance between a first transceiver 110 and second transceivers 120, 124 is shown. The distance measurement system has a first transceiver 110 and a clock 112 defining a first time zone, a second transceiver 120 and a clock 122 defining a second time zone, and a control unit 130 and a clock 132 defining a control unit time zone 132. In addition, another second transceiver 124 is depicted as having a clock 126 defining another second time zone. The first transceiver 110 includes a time communication module 144 and a measurement communication module 154. The second transceivers correspondingly include a time communication module 142 and a measurement communication module 152. In this example, a time communication connection 140 is established only between the first transceiver 110 and the second transceiver 120, while a measurement communication connection 150 is established between the first transceiver 110 and both the second transceiver 120 and the other second transceiver 124. There are additional connections between the second transceivers 120, 124 and the control unit 130.

[0047] Figure 2 A smartphone 200 having a first transceiver is shown.

[0048] Figure 3 A block diagram of a vehicle having a control unit 130, a second transceiver 120, and another second transceiver 124 is shown.

[0049] Figure 4 A flowchart of a method for measuring the distance between a first transceiver and a second transceiver is shown. The method has the following steps:

[0050] The second transceiver 120 determines 402 the time zone relationship Delta_SE2_SE1 between the second transceiver 120 and the first transceiver 110 and sends the time zone relationship Delta_SE2_SE1 to the control unit 130.

[0051] The control unit 130 receives 404 the time zone relationship Delta_SE2_SE1 and the time zone relationship Delta_SE2_SE1 and uses the time zone relationship Delta_SE2_SE1 to determine the time zone relationship Delta_ST_SE1 between the control unit time zone and the first transceiver 110.

[0052] Send 406 a distance measurement command to the second transceiver at a defined moment or during a defined time period in the first time zone.

[0053] The first transceiver sends 408 a measurement signal at the defined moment.

[0054] At a defined time or within a defined time period, switch the second transceiver 410 from an inactive measurement state to an active measurement state, receive the measurement signal, perform a distance measurement, and the second transceiver is switched back to the inactive measurement state.

Claims

1. A distance measurement system (100) for measuring the distance between a first transceiver (110) and a second transceiver (120, 124), the distance measurement system comprising a first transceiver (110) having a first time zone (112), a second transceiver (120) having a second time zone (122), a control unit (130) in a control unit time zone (132), Among them, the second transceiver being configured to determine a time zone relationship Delta_SE2_SE1 between the second transceiver and the first transceiver (110) and to send the time zone relationship Delta_SE2_SE1 to the control unit (130), wherein the control unit (130) is configured to: receive the time zone relationship Delta_SE2_SE1 and use the time zone relationship Delta_SE2_SE1 to determine a time zone relationship Delta_ST_SE1 between the control unit time zone and the first transceiver (110); wherein the first transceiver (110) is configured to send a distance measurement command to the second transceiver (120) at a defined moment or within a defined time period, wherein the first transceiver (110) is further configured to send a measurement signal at another defined moment, and wherein the second transceiver (120) is further configured to switch from an inactive receiving or measuring state to an active receiving or measuring state at these defined moments or within the defined time period, then receive the distance measurement command or the measurement signal, perform a distance measurement and switch back to the inactive measurement state.

2. The distance measurement system (100) according to claim 1, wherein, the first transceiver (110) comprises a first clock defining the first time zone, the second transceiver (120) comprises a second clock defining the second time zone, the control unit (130) comprises a control unit clock defining the control unit time zone, and wherein the first clock, the second clock and the control unit clock are configured to define their respective time zones independently of other time zones.

3. The distance measurement system (100) according to claim 1 or 2, wherein, the first transceiver (110) comprises a time communication module (144) and a measurement communication module (154), the second transceiver (120) comprises a time communication module (142) corresponding to the first transceiver and a measurement communication module (152) corresponding to the first transceiver (110), the time communication module of the first transceiver is configured to send a message for determining the time zone relationship between the first transceiver and the second transceiver to the second transceiver via a first communication protocol, and the measurement communication module of the first transceiver (110) is configured to send a measurement signal for determining the distance between the first transceiver and the second transceiver (120) to the second transceiver (120) via a second communication protocol.

4. The distance measurement system (100) according to claim 3, wherein, the first communication protocol is a Bluetooth communication protocol, and the second communication protocol is UWB, i.e., an ultra-wideband communication protocol.

5. The distance measurement system (100) according to claim 3, wherein, The message for determining the time zone relationship between the first transceiver and the second transceiver includes a transmission timestamp, and wherein the second transceiver (120) is configured to determine the time zone relationship based on the transmission timestamp and the reception timestamp.

6. The distance measurement system (100) according to claim 4, wherein, The message for determining the time zone relationship between the first transceiver and the second transceiver includes a transmission timestamp, and wherein the second transceiver (120) is configured to determine the time zone relationship based on the transmission timestamp and the reception timestamp.

7. The distance measurement system (100) according to claim 1 or 2, wherein, The distance measurement is a transmission time measurement, and wherein the first transceiver (110) and the second transceiver (120) are configured to determine the transmission time through communication between the first transceiver and the second transceiver (120).

8. The distance measurement system (100) according to claim 1 or 2, further comprising one or more additional second transceivers, wherein, These additional second transceivers each have their own independent time zones, and are configured to receive the time zone relationship Delta_SE2_SE1 from the second transceiver (120) or the control unit (130), and respectively determine their own time zone relationship Delta_SE2x_SE1 relative to the first transceiver (110), and are configured to At or within the defined moment, receive a distance measurement signal from the control unit (130), switch from an inactive measurement state to an active measurement state at this moment, then receive the measurement signal from these transceivers, perform distance measurement, and convert back to the inactive measurement state.

9. The distance measurement system (100) according to claim 1 or 2, wherein, The control unit (130) is integrated in the second transceiver (120, 124).

10. A vehicle (300) comprising a second transceiver (120, 124) and a control unit (130) as claimed in any one of claims 1 to 9.

11. A method (400) for measuring the distance between a first transceiver (110) and a second transceiver (120, 124), the method comprising the steps of: The second transceiver (120) determines (402) the time zone relationship Delta_SE2_SE1 between the second transceiver (120) and the first transceiver (110), and sends the time zone relationship Delta_SE2_SE1 to the control unit (130); The control unit (130) receives (404) the time zone relationship Delta_SE2_SE1 and uses the time zone relationship Delta_SE2_SE1 to determine the time zone relationship Delta_ST_SE1 between the control unit time zone and the first transceiver (110); Send (406) a distance measurement command to the second transceiver (120) at or during the defined moment in the first time zone; The first transceiver sends (408) a measurement signal at another defined moment; Switch (410) the second transceiver from an inactive measurement state to an active measurement state at these defined moments or during the defined period, receive the measurement signal, perform distance measurement, and convert back to the inactive measurement state through the second transceiver (120).

12. Use of the distance measurement system (100) as claimed in any one of claims 1 to 9 for a building access system.

13. Use of the distance measurement system (100) according to any one of claims 1 to 9 for non-contact payment or cash withdrawal.

14. Use of the distance measurement system (100) according to any one of claims 1 to 9 for an authorization system to enable machine functions.

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